ABSTRACT
Particulate material in the oceans plays a very significant role in the marine geochemical cycles of many elements, and the fluxes of particulates through the water column form a vital stage in the processes which control the fate of both dissolved and solid phases introduced into the marine environment. This chapter attempts to summarize the knowledge of the distribution, mineralogy, and chemistry of the particulates in sea water, and in doing so draws heavily on data relating to the natural components of the solids. Many hydrogenous solids are formed at the sediment-water interface. Others are either transported from the continental or estuarine regions or are precipitated in the water column, and so form part of the total suspended matter population. Various types of cosmogenous material have been identified in deep-sea sediments. These include cosmic spherules, teck-tites, and a number of cosmogenic nuclides.
